Farming Systems Programme (Botswana) & Norman, D. W. (1994). Farming systems research approach: A primer for eastern and southern Africa. Farming Systems Programme.
Chicago-referens (17:e uppl.)Farming Systems Programme (Botswana) och D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Gaborone, Botswana: Farming Systems Programme, 1994.
MLA-referens (8:e uppl.)Farming Systems Programme (Botswana) och D. W. Norman. Farming Systems Research Approach: A Primer for Eastern and Southern Africa. Farming Systems Programme, 1994.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.